Decolorizing substance



a Peas,- 1 .925.1-

WOLF KRITCHEVSKY,

OFCHICAGO. ILLINoIs, ASSIGNQR TO WILLIAM 'cn'non, TRUSTEE, or CHICAGO, ILLINOIS.

DECOLORIZING SUBSTANCE.

1T0 Drawing.

To all whom it may concern:

, Be it known that I, WOLF KRITCHEVSKY, a citizen of the United States, and resident of Chicago, in the county of Cook and State of 5 Illinois, have inventedcertainnew and useful' Imprb vements in a Decolorizing Substance, of which the following is a specification. I

. I am aware, that numerous efforts have been made 'to produce a chemical compound that will decolorize fabrics and-satisfactory results have been secured where the operation has been performed by skilled chemists or others who were carefully instructed in the performance of the steps of the process formaldehyde are mixed together in proper proportions with a solid organic or inorganic acid, an acid salt or a salt havingan acid reaction, a product is obtained which, when boiled in water with aniline dyes or colored fabrics, will cause the dye" to be chemically altered and lose its color and the dye will turn either white. or to its original colo r. Thisis true of dyes or articles colored with dyes, that on the treatment with hydrogen, are reduced to their components which are colorless, as azo dyes, azine dyes,

' some triphenylmethane dyes, some anthraquinone dyes, etc. a

Satisfactory results may be secured by emplo ing 8 ounces of sulphoxylate-formaldeby e zinc and 8 ounces of sodium bisulphite.

These are thoroughly mixed and produce one pound of the final product. It is in dry condition and may be sold direct tothe user and in the handling of the necessary cheinifabric or material that is colored with this Application filed July I8, 1924. Serial ms. 726,752.

in small packages. In the preferred use, assumlng the garment to be decolorized Weighs approximately'a pound and is dyed a medium shade, suflicient water to cover the garment completely is, boiled. To the bOlllIlg water is a/dded approximately one ounce of the described mixture, which is stirred until dissolved. Thereafter the garment is immersed in the liquid, and the boilmg is continued for five to twenty minutes until the "color- ,is eliminated.

Instead of the compound described I may to employ 5 ounces of sulphoxylate-formaldehyde of zinc, or' some other metal, with 11- ounces of aluminum sulphate. This pro-w duct is practically entirely soluble in water. Or I may employ 8 ounces of any of them; sulphoxylate-formaldehydes with 8 ounces of tartaric, citric, oxalic, or some other organic acid. In any case the useis the same as that described.

The only condition in the selection of sub- 7 stances to be employed with theasulphoxy' late-formaldehyde salt is that the acid shall be in the form of a solid and shall-be soluble I in water. Upon entering into solution theacid which is released reacts with the metal 7 salt to release free sulphoxylate-formaldehyde and this substance reacts with and' neutralizes the dye in the fabric. As an alternative method of use I may dampen the substance, spread it evenly over so the article to be decolorized, spread a second pieceof fabric thereover and employ a hot s iron. Other methods of use may possibly be devised in which the novel substance can be utilized. It will be understood, however, I

presence of water which will release sulficient acid to liberate thefree sulphoxylatehaving an acid reaction. in the presence of formaldehyde when the mixture enters-into water which will release sufiicient acid to 10 solution. liberate the free sulphoxylate-formaldehyde I 3. A water, soluble dry mixture, substanwhen reaction occurs between the subtially equal parts of a sulphoxylat'e formalstances.

dehyde salt, and sodium bisulphite. Signed at Chicago, 111., this 7 day of July,

4. A dry mixture'of a sulphoxylate-for- 1924.

vmaldehyde. salt, and an amount of a solid WOLF KRITCHEVSKY. 

